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Domain: physicscentral.com
Stories and comments across the archive that link to physicscentral.com.
Stories · 26
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Scientists Propose Using Cold War Era Weapons To Deflect Asteroids (blastingnews.com)
MarkWhittington writes: Many people are considering what to do if an asteroid was headed for a collision with Earth. One such collision wiped out the dinosaurs 65 million years ago. Now, films such as "Armageddon" and "Deep Impact" depict what might happen if Earth were threatened with a similar event in modern times. As a result, some people are repurposing weapons that were built or envisioned during the Cold War to confront the celestial threat, from old ICBMs to space-based laser systems. -
The Fascinating Science Behind Beer Foam
RenderSeven writes "Science has so far been at a loss to explain why tapping a beer bottle with another causes it to explosively foam over. Thanks to a grant from the Spanish Ministry of Economy and Competitiveness, a research team at the University of Madrid studying fluid mechanics has found the answer with some fascinating slow-motion video. Their soon-to-be-published paper found that tapping the bottle (or shooting it with a laser) causes a series of compression and expansion waves, that generate unstable buoyant plumes, quickly turning most of the liquid into foam. PhysicsBuzz notes that the process is very rapid and nearly unstoppable once started." -
Imprisoned Physicist Honored For Refusing To Work On Iran's Nuclear Program
New submitter I3MOUNTAINS writes "Omid Kokabee, a University of Texas graduate student who has been imprisoned in Iran for more than two years, received the American Physical Society's Andrei Sakharov human rights prize for refusing to collaborate on the country's nuclear program. In May, an Iranian court sentenced him to ten years in prison for 'communicating with a hostile government' and receiving 'illegal earnings.' The so-called 'illegal earnings' were the student loans he received while in Texas." -
Crowd Funding For Crank Physics
BuzzSkyline writes "A new design for bicycle cranks violates basic principles of physics, but that's not stopping the inventor of Z-Torque cranks from trying to raise thousands in start-up capital through crowd funding." The picture looks intriguing for a fleeting moment before it looks silly. Covered in similar style at a site I'm glad to discover exists, the Bicycle Museum of Bad Ideas. -
The Laws of Physics Trump Traffic Laws
New submitter HeLLFiRe1151 sends this quote from Physics Central: "Here's a practical application for your physics education: using math to successfully beat a traffic ticket in court. Dmitri Krioukov, a physicist based at the University of California San Diego, did just that to avoid paying a fee for (purportedly) running a stop sign. Krioukov not only proved his innocence, but he also posted a paper detailing his argument online (PDF) on the arXiv server." -
Microgravity Coffee Cup
BuzzSkyline writes "Despite the fact that astronauts have been eating and drinking out of tubes for decades, it's actually possible to drink from an open-top cup in space. Astronaut Don Pettit recently downlinked a video that shows him slurping coffee from a cup he kludged out of plastic sheet. It appears to work pretty much like a cup on Earth, even in freefall aboard the International Space Station, thanks to capillary action." -
Water Droplets In Orbit On the International Space Station
BuzzSkyline writes "Astronaut Don Pettit, who is aboard the International Space Station right now, puts charged water droplets into wild orbits around a knitting needle in the microgravity environment of the ISS. A video he made of the droplets is the first in a series of freefall physics experiments that he will be posting in coming months." -
Fine Structure Constant May Not Be So Constant
BuzzSkyline writes "According to a post at Physics Buzz, 'Just weeks after speeding neutrinos seem to have broken the speed of light, another universal law, the fine structure constant might be about to crumble.' Astronomical observations seem to indicate that the constant, which controls the strength of electromagnetic interactions, is different in distant parts of the universe. Among other things, the paper may explain why the laws of physics in our corner of the universe seem to be finely tuned to support life. The research (abstract) is so controversial that it took over a year to go from submission to publication in Physical Review Letters, rather than the weeks typical of most other papers appearing in the peer-reviewed journal." -
Researcher Claims Magnets Can Affect Blood Viscosity
BuzzSkyline writes "A few minutes in a high magnetic field (1.3 Tesla) is enough to thin blood by 30%, potentially leading to a new drug-free therapy to prevent heart attacks. The powerful field causes blood cells to line up in chains that flow much more easily than randomly-scattered individual cells, according to research scheduled to appear this month in the journal Physical Review E." I can't help thinking of Penn & Teller's look at magnets-as-medicine, though at least the idea here described sounds testable and doesn't rely on the power of suggestion. -
Four Physicists Arrested After SSC Break-In
An anonymous reader writes with a not-unexpected followup to one of the break-ins of the century, when a group of curious scientists decided to see what was left of the uncompleted giant collider project in East Anglia Texas L.A. Angola . From the article: "A team of four physicists was arrested this morning at the headquarters of the American Physical Society (APS) in College Park, MD. Plain-clothed Tastefully-dressed Nude Well-basted officers from the Department of Homeland Security entered the building around 8:30 a.m. and detained the suspects without tasers a prayer flatulance incident . The group is charged with breaking and entering a secure government facility, destruction of government property, stealing national secrets and parking illegally." -
Breaking Into the Super Collider
BuzzSkyline writes "A group of physicists went AWOL from the American Physical Society conference in Dallas this week to explore the ruins of the nearby Superconducting Super Collider. The SSC was to be the world's largest and most ambitious physics experiment. It would have been bigger than the LHC and run at triple the energy. But the budget ran out of control and the project was scrapped in 1993." -
Hawking: No 'Theory of Everything'
Flash Modin writes "In a Scientific American essay based on their new book A Grand Design, Stephen Hawking and Leonard Mlodinow are now claiming physicists may never find a theory of everything. Instead, they propose a 'family of interconnected theories' might emerge, with each describing a certain reality under specific conditions. The claim is a reversal for Hawking, who claimed in 1980 that there would be a unified theory by the turn of the century." -
NASA Creates an Alien's Eye View of Solar System
Flash Modin writes "Using the Discover supercomputer — which is capable of 67 trillion calculations per second — astronomers at NASA Goddard have created a series of images of what our solar system would look like to an alien astronomer at various points in time. Their simulations track the interactions of 75,000 dust grains in the Kuiper Belt, and show that while the planets would be too dim to detect directly, aliens could deduce the presence of Neptune from its effects on the icy region. Strikingly, the images resemble one taken by Hubble of the star Fomalhaut. NASA has put out a cute video to go with the announcement as well." -
Construction of French Fusion Reactor Underway
GarryFre writes "It has been said that fusion is 50 years away for quite a few decades, but now work has actually been started. Digging has begun in the south of France on the planned site for France's first fusion reactor. A tokomak is a torus shaped magnetic confinement device which is necessary to withstand the temperatures associated with fusion that are so high, solid materials can't hold them. As such, the building represents the future core of ITER (International Thermonuclear Experimental Reactor.) It will be interesting to see if it takes 50 years to build it." -
Two Research Groups Create 'Electric Skin'
Flash Modin writes "Two separate teams, one from UC Berkeley and the other from Stanford, have created distinct types of artificial skin that could find uses in prosthetics or artificial intelligence (Data in First Contact, anyone?). The first team coupled organic electronics with an elastic polymer to make electric skin that could sense a butterfly landing on it (abstract). The second team put a flexible material over a conductive rubber compound which had transistors implanted in it. The device can sense touch when the rubber is compressed, changing the electrical resistance (abstract)." -
(Don't) Make Your Own Fire Tornado
Flash Modin writes "In the last two weeks, both water and fire tornadoes have been widely covered by the media. As any physicists would have, we immediately thought 'I want to do that!' SO... You should absolutely, under no circumstances, not attempt to recreate the following fire tornado; but if you did, here's exactly what you would need, how you would do it, and what it would look like." -
Scientists Find a Better Way To Pour Champagne
BuzzSkyline writes "It's better to pour Champagne the way a good bartender draws a beer, by running it down the inside surface of the glass. The revelation, which appears in July 2010 issue of the Journal of Agricultural and Food Chemistry, flies in the face of age-old French traditions, which require the bubbly to be poured in a stream that free-falls straight down the center of a champagne flute. By using infrared thermography to image the carbon dioxide that escapes over the rim of a Champagne glass for various style pours, the researchers proved that the gentler, beer-like technique allows the wine to retain more of the dissolved gas that is critical to the whole Champagne experience." -
Lasers Approach Their Ultimate Intensity Limit
Flash Modin writes "Death Star style superlasers? Don't bet on it. High-power lasers currently in development appear to be nearing the theoretical laser intensity limit, according to new research set to be published in the journal Physical Review Letters. Ultra-high-energy laser fields can actually convert their light into matter as shown in the late '90s at the Stanford Linear Accelerator (SLAC). This process creates an 'avalanche-like electromagnetic cascade' (also known as sparking the vacuum) capable of destroying a laser field. Physicists thought it might be a problem for lasers eventually, but this work indicates the technology is much closer to its limit than researchers believed. A preprint is available here." -
World's Tiniest Radiometer To Power Medical Scanner
BuzzSkyline writes "University of Texas physicists have built the world's smallest radiometer. The minuscule radiometer is only 2 millimeters across and operates on the same principles as the common light-driven toy, which consists of spinning black and white vanes in a partially evacuated bulb. The researchers attached a mirror to their tiny radiometer and used it to rapidly scan a laser beam. Their hope is that they will be able to incorporate the radiometer into catheters to drive scanners that produce medical images of the interiors of blood vessels and organs. The devices would replace micromotors in conventional catheter-based scanners, eliminating the need to run potentially risky electrical currents into the body." -
Body Heat Energy Generation
BuzzSkyline writes "Researchers in Belgium have developed devices to harvest the waste heat our bodies throw off in order to convert it to electricity to run devices such as a wristband blood oxygen sensor and an electrocardiogram shirt. As a side benefit, the power sources help cool you down and keep you looking cool, all while running sundry micropower devices. In fact, the researchers mention that the energy harvesting head band works so well that it can get uncomfortably cold. In that case, they say, 'This problem is solved in exactly the same way as someone solves it on the body level in cold weather: a headgear should be worn on top of the system to limit the heat flow and make it comfortable.' But it would be such a shame to cover up the golden heat-harvesting headband with a hat." -
Lego Blocks Simulate Microfluidic Filters
BuzzSkyline writes "Researchers at Johns Hopkins University are playing with Lego blocks to discover how arrays of nanoscopic obstacles could sort cells and other tiny particles by size. Ball bearings dropped through an array of Lego pieces submerged in glycerin serve as an analogue of the tiny systems, with bearings of different sizes taking different paths through the array. An academic paper describing the Lego research recently appeared in the journal Physical Review Letters (subscription required)." -
Military Helmet Design Contributes To Brain Damage
BuzzSkyline writes "Improvements in helmets have helped modern soldiers survive bullets and blasts that would have killed them in past wars. But increasing numbers of soldiers are suffering long lasting brain damage from explosions, partly as a result of what appears to be a flaw in helmet designs. Although the blast itself may not accelerate the brain inside a soldier's head enough to cause injury, shockwaves that make it through the space between a helmet and a soldier's head can cause the skull to flex, leading to ripples in the skull that can create damaging pressures in the brain. Simulations that relied on 'code originally designed to simulate how a detonated weapon rattles a building or tank' could lead to new helmets that reduce the traumatic brain injuries that many soldiers suffer as a result of improvised explosive devices and other moderate-sized blasts. The research is due to be published in Physical Review Letters, but a pre-print of the entire article is currently available on the Physics ArXiv." -
Obstacles Near Emergency Exits Speed Evacuation
BuzzSkyline writes "Despite fire codes that require emergency exits be clear of obstacles, some types of obstacles actually speed evacuation. The counterintuitive conclusion resulted from a series of experiments performed at a TV studio in Japan. Researchers from the University of Tokyo asked 50 volunteers to exit the studio through a narrow door. Video tapes of the experiments show that people made it out quickest when a pole was placed about 30 degrees to one side of the exit. The lead researcher believes an obstacle reduces jamming and friction among people in crowds by decreasing conflicts as the crowd presses toward the exit. A paper describing the research is scheduled to appear in the journal Physical Review E in September, but a preprint is available on the Physics Arxiv." -
Rude Drivers Reduce Traffic Jams
BuzzSkyline writes "Traffic jams are minimized if a significant fraction of drivers break the rules by doing things like passing on the wrong side or changing lanes too close to an intersection. The insight comes from a cellular automata study published this month in the journal Physical Review E. In effect, people who disregard the rules help to break up the groups that form as rule-followers clump together. The risk of jamming is lower if all people obey the rules than if they all disobey them, according to the analysis, but jamming risk is lowest when about 40 percent of people drive like jerks." -
Electricity From Salty Water
BuzzSkyline writes "It's possible to produce energy by simply mixing fresh and salty water. Although chemists and physicists have long known about the untapped energy available where fresh water rivers pour into salty oceans — it's equivalent to 'each river in the world ending at its mouth in a waterfall 225 meters [739 feet] high' — the technology for exploiting the effect has been lacking. An Italian physicist seems to have solved the problem with the experimental demonstration of a 'salination cell' that creates power given nothing more than input sources of salty and fresh water. The researcher believes that this renewable, environmentally friendly energy source could be deployed in coastal areas and could provide another addition to the green-tech roster. A paper describing the technology is due to be published in an upcoming issue of the journal Physical Review Letters." -
Earthquake Invisibility Cloak
BuzzSkyline writes "The same folks who brought us the tsunami invisibility cloak last year have now come up with an earthquake invisibility cloak. They show that a platform made of just the right configuration of elastic rings could make a structure invisible to earthquakes by effectively steering a quake around the structure. It doesn't work well for compression waves, but the researchers claim it could hide buildings from the slower-moving, more destructive shear earthquake waves. The research is due to be published soon in the journal Physical Review Letters."